A new pay-per-use scheme for the protection of FPGA IP

Field-programmable gate arrays (FPGAs) are widely applied in various fields for its merit of reconfigurability. The reusable intellectual property (IP) design blocks are usually adopted in the more complex FPGA designs to shorten design cycle. IP infringement hence becomes a concern. In this paper, we propose a new pay-per-use scheme using the lock and key mechanism for the protection of FPGA IP. Physical Unclonable Function (PUF) is adopted to generate a unique ID for each IP instance. An extra Finite State Machine (FSM) is introduced for the secure retrieval of PUF information by the FPGA IP vendor. The lock is implemented on the original FSM. Only when the FPGA developer can provide a correct license, can the FSM be unlocked and start normal operation. The FPGA IP can hence be protected from illegal use or distribution. The scheme is applied on some benchmarks and the experimental results show that it just incurs acceptably low overhead while it can resist typical attacks.